Firearm Injuries

Which feature best distinguishes an entrance wound from an exit wound in a firearm injury?

A 32-year-old man is brought to the mortuary with a single gunshot wound to the chest. On autopsy, the wound shows a 0.8 cm diameter with punched-out clean margins, an abrasion collar, and inward beveling of the rib. Which feature best distinguishes this entrance wound from a potential exit wound on the opposite side of the chest?

In a firearm injury, the temporary cavity is most likely to cause significant secondary organ damage in which of the following scenarios?

A 32-year-old man is brought to the emergency department with a gunshot wound to the left anterior chest at the 4th intercostal space. On examination, he is conscious, blood pressure 95/60 mmHg, heart rate 118/min, respiratory rate 28/min. There is a small entry wound with a surrounding zone of abrasion and soot deposition. Chest X-ray shows a pneumothorax and mediastinal widening. What is the most likely distance from which the firearm was discharged?

A 32-year-old man is brought to the emergency department with a gunshot wound to the left chest. On examination, the entry wound is 8 mm in diameter with a surrounding abrasion collar and marginal blackening. The exit wound on the right chest is larger and more irregular. Which of the following statements about firearm injuries is NOT true?